High-speed MALDI MS/MS imaging mass spectrometry using continuous raster sampling

J Mass Spectrom. 2015 Apr;50(4):703-10. doi: 10.1002/jms.3579.

Abstract

A matrix-assisted laser desorption/ionization time of flight/time of flight tandem mass spectrometer (MALDI TOF/TOF) has been used for high-speed precursor/fragment ion transition image acquisition. High-throughput analysis is facilitated by an Nd:YLF solid state laser capable of pulse repetition rates up to 5 kHz, a high digitizer acquisition rate (up to 50 pixels/s), and continuous laser raster sampling. MS/MS experiments are enabled through the use of a precision timed ion selector, second source acceleration, and a dedicated collision cell. Continuous raster sampling is shown here to facilitate rapid MS/MS ion image acquisition from thin tissue sections for the drug rifampicin and for a common kidney lipid, SM4s(d18:1/24:1). The ability to confirm the structural identity of an analyte as part of the MS/MS imaging experiment is an essential part of the analysis. Additionally, the increase in sensitivity and specificity afforded by an MS/MS approach is highly advantageous, especially when interrogating complex chemical environments such as those in biological tissues. Herein, we report continuous laser raster sampling TOF/TOF imaging methodologies which demonstrate 8 to 14-fold increases in throughput compared with existing MS/MS instrumentation, an important advantage when imaging large areas on tissues.

Keywords: MALDI; MS/MS; TOF/TOF; continuous raster; drug imaging; imaging; lipid imaging.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Chemistry
  • Histocytochemistry
  • Kidney / chemistry
  • Lipids / analysis
  • Lipids / chemistry
  • Liver / chemistry
  • Mice
  • Molecular Imaging / methods*
  • Pharmaceutical Preparations / analysis
  • Pharmaceutical Preparations / chemistry
  • Rats
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Tandem Mass Spectrometry / methods*

Substances

  • Lipids
  • Pharmaceutical Preparations